The present invention relates generally to a vehicle monitoring system and method, and more particularly to a combined system and method to monitor and communicate the instantaneous rate of consumption usage, along with the limits of the available rate of consumption, both positive and negative.
The need to reduce fossil fuel consumption and emissions in automobiles and other vehicles predominately powered by internal combustion engines (ICEs) is well known. Vehicles powered by electric motors or other power sources attempt to address these needs. Other alternative solutions combine a smaller ICE with electric motors or other power sources into one vehicle. Vehicles that combine the advantages of an ICE vehicle and an electric vehicle are typically called Hybrid Electric Vehicles (HEVs). See generally, U.S. Pat. No. 5,343,970 to Severinsky.
The desirability of combining an ICE with other power sources such as an electric motor is clear. There is great potential for reducing vehicle fuel consumption and emissions with no appreciable loss of vehicle performance or drive-ability. An HEV not only allows the use of smaller ICEs, but also allows regenerative braking, electric power assist in the vehicle""s powertrain, and even powering the vehicle without assistance from the ICE.
New ways must be developed to operate these dual powered vehicles. In conventional ICE vehicles, several familiar gauges provide vehicle state information such as vehicle speed, engine temperature, engine RPMs, and alternator function. The HEV and other more sophisticated and complex vehicles must convey new types of vehicle state information to the operator. These monitoring systems must be simple and easy to read.
For example, operators must be notified of HEV state information on available power assist limits by stored power sources such as batteries because the operator must known when powertrain requests cannot be met under present vehicle operating conditions. More specifically, in an electric or partial electric (hybrid) vehicle, the available power to accelerate the vehicle may become inconsistent due to many factors. For example, when the battery is at a low state of charge or excessively warm, the battery power available to a vehicle""s electric motors may be temporary limited. The operator must be aware of these conditions and know when the battery power is limited so that a maneuver that may require battery power to the electric motor is not attempted.
Battery energy displays, gauges, or monitors for electric vehicles are known in the prior art. U.S. Pat. No. 6,175,303 B1 to Theofanopoulos et al. describes a battery energy-measuring device indicating maximum available battery current on an analogue scale as a percentage. U.S. Pat. No. 5,532,671 Bachman et al. signals to an operator of an electric vehicle that the battery is at a reduced state of charge by requiring the accelerator to be depressed farther to provide an equivalent accelerator command to the controller that controls the motor. U.S. Pat. No. Des. 378,500 to Nakai et al. describes an ornamental design for residual battery capacity and electric vehicle range.
It is also common in an electric or partial electric vehicle to include an analog gauge that displays whether the operator is requesting power assist, regenerative braking or battery charging. Unfortunately, the known indicators for electric and HEV vehicles are often complicated and confusing to an operator and clutter the vehicle dashboard.
Accordingly, the present invention provides an improved method and system to monitor vehicle operation state and operator requests.
The main object of the present invention is to combine into a single, easy to read gauge information indicating the current vehicle operating state and the ability to increase power assist.
It is a further object of the present invention to provide a single gauge that combines the available rate of power consumption limits and instantaneous rate of consumption usage.
It is a further object of the present invention to provide a vehicle gauge that displays whether an operator is requesting power assist, regenerative braking or battery charging while also displaying the amount of power assist, regenerative braking or battery charging that is possible for the vehicle under present operating conditions.
The instantaneous rate of consumption usage or charge can be limited to the available rate of power consumption or charge limits by a vehicle system controller (VSC) or similar type controller. The invention can use analog needles or light emitting diodes in various configurations as well as adding warning indicator lamps or chimes when the instantaneous rate of consumption usage approaches or exceeds the available rate of power consumption limits.
Other objects of the present invention will become more apparent to persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying figures.